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Carbone

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No Woman, No Drive. Pékin interdit aux compagnies aériennes chinoises de payer la taxe carbone UE. Pékin a interdit aux compagnies aériennes chinoises de payer la taxe carbone imposée par l’Union européenne sur les compagnies aériennes, d’augmenter les frais de transport ou d’ajouter tout autre frais supplémentaire sans l’aval du gouvernement.

L’Administration de l’aviation civile de Chine a indiqué qu’elle avait été autorisée par le Conseil des Affaires d’État à notifier ces interdictions à toutes les compagnies aériennes domestiques. Pour les autorités chinoises, la décision de l’Union européenne de faire payer les avions atterrissant ou décollant des aéroports de l’Union pour leurs émissions de carbone va à l’encontre des principes de la Convention cadre des Nations Unies sur le changement climatique, et des règlements internationaux de l’aviation civile. On estime à environ 4.000 le nombre de compagnies aériennes qui devront se soumettre à la taxe carbone de l’Union. Lbruno.home.cern.ch/lbruno/documents/Bibliography/LHC_Note_78.pdf. Carbone: Mesures du point de fusion du graphite et les propriétés du carbone liquide (un examen pour 1963-2003)

Scientific literature on the melting temperature of graphite and its properties in melting is reviewed, beginning with the study by Bundy in 1963 and proceeding up to 2003. Data obtained by Pirani in 1930 that has been quoted in some recent publications is also considered. Successive experimental data and theoretical predictions on the melting point of carbon are summarized. The history of carbon studies, starting in 1963, is given, covering both laser and electrical heating of the graphite. The main divergence in the experimental results is in the value of the true melting temperature of graphite in the range of 4000 or 5000 K. The paper first describes laser heating. Pulsed laser heating of graphite usually shows the absence of a melting temperature plateau in the heating of a low-density graphite specimen (only a deflection point is observed on the increasing signal of the pyrometer).

The volume electrical heating of graphite is then discussed. Copyright © 2005 Elsevier Ltd. Carbone: graphite-liquide-vapeur sous pression point triple et la densité de carbone liquide. A detailed experimental investigation of the graphite-liquid-vapor triple point using a 400 W Nd:YAG continuous-wave laser as the heat source was completed and the triple point pressure accurately placed at 107 ± 2 atm (10.8 ± 0.2 MPa). Both X-ray diffraction and detailed microstructure of the recrysallized graphite were obtained to confirm melt. Careful experimental procedures were employed to address some of the remaining uncertainties in previous carbon triple point studies. These included accurate pressure measurements combined with apparatus designed to minimize pressure excursions. Also systematic melt experiments were completed in helium and argon as a function of sample size and laser power density to assure that sufficient power was available to produce melt at the triple point pressure and to prove, for the first time, that only carbon vapor was present at the sample surface during melting.

Le carbone controversée solide-liquide-vapeur point triple.